The problem:

​

How to express a data need?, Which tool (s) to use to formulate its needs? What reasoning to use?

So many questions that J.D WARNIER will try to solve with LDR, we will see how the analytical approach which consists of starting from the set to the element allows us to obtain the desired results.

​

First of all, it should be noted that when talking about COMPUTER SYSTEMS, there is no mention of the computer, but a logical system for storing and processing data, the computer being only the means.

​

Another crucial precision is that there is a bijection between the computer system (logic) and the company or management unit to which it corresponds. This leads us to say that before any study of the data of a system, it is imperative to define the latter in understanding so that everyone knows perfectly the limits of the study in progress. We must not try to work on a system that is too large in terms of production flows, but remain within the limits of the human being, we must not hesitate to subdivide a company into management units and thus define several logical computer systems Which will allow a simpler study. If to illustrate this point I could take as an example the AMTRAK company, you easily imagine that it would be quite impossible to deal with the subject in its entirety! It is imperative to subdivide the company into subsets (regardless of the subdivision criterion employed) to human size and therefore to define several corresponding computer systems.

​

​